Tubing cutter



'May 7,1940.

c. HOWARD TUBING GUTTER Filed. July 10. 19:57'

2 Sheets-Sheet 1 May 7, 1940. c, HOWARD 2.200.172

TUBING cuTTER` Filed July 10. 1957 2 Sheets-Sheet 2 [lll/00, 33

Patented May 7, 1940 UNITED STATES PATENT oFFicE A I 2,200,112

Cliord Hcwardfklcatncity, l

Application July 10, 1937, serial No. um: claims. (c1.- 164-03) This invention relates to well tools and relates more particularly to a tool for cutting well tubing and other tubular objects in wells. A general object of this invention isto provide a practical,

dependable and compact well tubing cutter.

Another object of this invention is to provide a tool for cutting or severing tubing and the like in a well that is under the full control of the operator at all times and that may besuccessively operated any required number of times before being withdrawn from the well.

Another object of this invention to provide l a tubing cutter in which the cutting knives are .fed outwardly and then maintained in cutting contactwith the.pipe or tubing in such a manner thatthey are not subjected to excessive forces and do not jump, chatter or bite into the pipe or tubing.

Another object of this invention is tol provide a tubing cutter in which the feed pressure applied to the cutters or knives may be varied at will by the operator at the well derrick.

l Another object of this invention is to provide a tubing cutter of the character mentioned embodying a novelfriction control means for effecting the actuation and the outward feeding ofthe cutters or knives,

AnotherV object of this invention is to provide a tubing cutter of the character mentioned in which the knives are actuated and fed outwardly by vrotation of the operating string and by the application `of a downward pressure on the tool and the cutting aetionof the knives may bev governed as desired by varying;l the rate of rotation and the intensity of the downward force. y

Another object of this invention is to 'provide a tubing cutter of the character mentionedthat is simple and inexpensive to manufacture and recondition.

vA further object of this Y a simple, practical'and improved slip assembly or tail-piece for a well tool. 4 The various objects andfeatures of my invention will be fully-understood from the following detailed description of a typical preferred form and application of the invention, throughout whichdescrlption reference is made to the accompanying drawings, in which: Y

Fig. 1 is a side elevation of the tool provided by this invention in position in a well tubing showing the parts in the normal or retracted positions.

Gil

showingjthe knives inthe retracted positions.

Fig. 3l is 'a view similar to Fig. 2 showing the invention -is to provide tary longitudinal detailed sectional view of the Alower portion of the tool showing the parts in the actuated positions. Fig. 7 is a transverse detailed sectional view taken-as indicated by line 'I-'I on Fig. 6, and Figs. 8 and 9 are enlarged, transverse detailed sectional views taken as indi- .cated by lines 8-8 and 9 9, respectively, on

Fig. 1.

The present invention may be'embodied in tools for cutting tubular objects of various sizes and .natures and is concerned primarily with atool for cutting tubular objects in wells. In the following detailedv description I will describe the invention embodied in a tubing cutter for cutting well tubing in a well. It is to be understood that the invention is not to be construed as limited or restricted to the'specic form or application of the invention about to bev described,- but is to be taken as including any features or modications Y that may fall within the scope of the claims.,y

' The .improved tubing cutter providedby this invention includes, generally, a stem or mandrel I0, a slip assembly or tail-piece I I on the mandrel I0 operable to grip the interior of a tubing T to remain stationary therewith, a knife carrier I2 turnable on the mandrel IU, knives I 3'on the carrier I2 operable outwardly against the tubing T upon relative turning between the mandrel I0' and the carrier I2, means Ilnormally holding the knives I 3 retracted anda friction means or` I friction brake means I5 between the knife carrier I2 and the tail-piece il operable to resist turning of the carrier I2 whereby the knives I3 Amay be operated by rotation of the mandrel III.

The mandrel l0 supports the various other parts of the tool and is adapted toA be connected with the lower end of an operating string S of pump rods, or the like. In practice the mandrel I0 may be a length of rod or cylindrical stock of uniform diameter; A sub I6 is threaded-on the upper-end of the mandrel I0 and has a socket I1 in its upper end to receive the threaded end of the operating string S. A .pin I8 is 'passed 4'through a transverse opening in the sub I6 and cooperates with a notch I9 inthe upper end ofV l the mandrel Ill to prevent unthreading of the sub I6, from the mandrel. A nut 2 0 is threaded on the lower end ofthe mandrel III. 'I'he nut is shaped to guide the tool through the tubing T and may be locked in place on the mandrel by a set screw 2|. An upwardly projecting tubular extension 22 is provided 'on the nut 20 and surrounds the lower portioneof the mandrel I0.

The slip assembly or tail-piece I| is arranged around the lower portion of the mandrel I0. The tail-piece II includes a body 23 having a central longitudinal opening 24 shiftably and rotatably receiving*I the mandrel II). The body 23 has an extension 25A of reduced diameter extending around the mandrel ID. The body 23 of the tailpiece is provided with downwardly and inwardly inclined external surfaces 26. In the particular construction illustrated there are two diametricallygopposite inclined surfaces 26 provided on the body 23. Longitudinally extending dovetailed grooves 21 are provided in the surfaces 26. The bottom walls or inner walls of the dovetailed grooves '21 are inclined and are parallelI with the surfaces 26. Two at faces or flat walled grooves 28 are provided in the body 23 and are spaced substantially 90 from the surfaces 26. The slip assembly or tail-piece I I further includes an upper ring 29 and a lower ring 30. The upper ring 29 surrounds and is shiftable on the body cludes slips 33 for gripping the interior of the tubing T. 'I'he slips 33 are wedge-like members having inclined inner surfaces slidable on the inclined surfaces26 of the body 23. Dove-tailed tongues 34 are provided on the inner sides of the slips 33 and operate longitudinally in the grooves '21. The outer sides of the slips 33 are shaped to conform to the interior of the tubing T and Ahave horizontal wickers or teeth 35 for gripping the tubing. 'I'he teeth 35 point or face downwardly and outwardly and are preferably interrupted by vertical notches to be effective in preventingturning of the body 23, and the parts connected therewith, relative` to the tubing.

Means is provided to connect the slips 33 and the rings 29 and 30 against relative vertical movement whereby the vertical movement of the body 23 relative to the rings effects actuation of the slips. Notches 36 are provided in the upper and lower ends of the slips 33 and ngers 31 project axially or longitudinally from the rings 29 and 30 to cooperate with the notches 36. The ngers 31 cooperate with the notches 36 to prevent or limit vertical movement of the slips 33 relative to the rings 29 and 36 and the fingers 31 engaging in the notches 36 hold the'rings in position where the springs 3| are aligned with the grooves 28.

A releasable connection is provided between the tail-piece II and the mandrel III whereby the tool may be run through the tubing T with the slips 33 retracted and may be readily conditioned for operation at the selected position in the well. The connection between the tail-piece II and the mandrel I0 includes an external thread 38 on the nut extension 22 and an internal thread 39 on lthe interior of the ring 30 cooperable with the thread 38. The threads 38 and 39 are coarse or heavy and preferably have a substantial pitch. 'I'he releasable connection further includes a helicoidal face 40 on the upper end of the nut 2|) and a complementary face 4I on the lower .end of the ring 30. 'I'he faces 46 and 4I have substantially the same pitch as the threads 38 and 39.

'I'he high and low ends of the face 40 are connected by, or terminate at an abrupt Vertical shoulder 42 and the face 4| has a similar shoulder 43. When the threads 38 and 39 are fully made up the shoulder 43 cooperates with the shoulder 42 to prevent tightening of the threads so that the nut 20 may be easily disconnected or unthreaded from the tail-piece ring 30.

Fig. 1 of the drawings illustrates the nut 2l) and the tail piece ring 30 threaded together with the shoulders 42 and 43 in cooperation. To release the nut 20 from the ring 30 the mandrel I0 is turned in a right-hand direction to unscrew the threads 38 and 39. During this. turning of the mandrel III the springs 3| frictionally bear against the interior of the tubing T to resist rotation of the rings 29 and 30. Following the release of the nut 2l) from the ring 30 the mandrel I0 is moved downwardly and the inclined surfaces 26 cooperating with the inner sides of the slips 33 force the slips outwardly against the interior of the tubing T. 'Ihe slips 33 are adapted to tightly grip the interior of the tubing T to hold the body 23 and the parts connected therewith against rotation and downward movement.

The knife carrier I2 is provided to support the knives I3 and is arranged around the mandrel I0 below the sub I6. In the preferred construction the knife carrier I2 is a tubular cylindrical member having a central longitudinal opening 44 shiftably and turnably receiving the stern III. The upper and lower ends of the carrier I2 are preferably flat and horizontal. The carrier I2 is adjacent the sub I6, the upper end of the cari rier being spaced a short distance below the lower end of the sub I6.

The knives I3 are supported by the carrier I2 and are under the control of the means I4 and the friction brake means I5. The knives I3 are arranged at the top or upper end of the carrier I2. In accordance with the invention the knives I3 are pivoted dog-like elements. Pivot pins 45 project from the upper end of the carrier I2 and the knives I3 are pivoted on the pins 45. 'I'he I -knives I3 are alike or identical.

In the form of the invention illustrated in the drawings there are three knives I3, the pins 45 supporting the knives being equally spaced about the longitudinal axis of the tool. The knives I3 extend rearwardly from theirvpivotal mountings relative to the right-hand direction of rotation of the tool. are sharpened to form cutting edges 46. The lower sides of the knives I3 may rest on the upper end of the carrier I2 and the rear ends of the knives may have their upper and lower surfaces tapered toward the cutting edges 46. 'I'he inner sides or surfaces of the cutters- I3 extending forwardly or away from the cutting edges 46 are in the nature of cam surfaces 41. The cam surfaces 41 are curved or convex as best illustrated in Figs. 2 and 3 of the drawings. The outer sides of the knives I3 have depressions 48 adjacent their forward ends relative to the right-hand di- The rear outer corners of the knives I3 v rection of rotation. The knives I3 are normally ing with the knives I3 to effect their actuation or outward pivoting upon relative vturning movement between the carrier I2 and the sub I6. Fingers or blades project downwardly from the lower end of the sub I6 to cooperate with the cam faces 41 of the knives. The blades 50 may be vane-like parts whose forward faces for cooperating with the cam faces 41 are tangent to a small circle concentric with the longitudinal axis of the tool. The blades 58 may extend between the inner and outer peripheries of the sub I6. When the knives I3 are in their normal retracted positions the cam faces 41 may be in cooperation with the blades 50. Upon righthand turning movement of the sub I6 and mandrel III 'relative to the carrier I2 the blades 58 cooperating with the faces 41 swing the knives I3 outwardly to their active cutting positions.

Stops 5I project downwardly from the lower end of the sub I6 to limit. the outward pivoting of the knives I3. 'I'he stops 5I are adjacent the outer periphery of the sub I6 and are located to be received in the depressions 48 when the knives I3 are swung outwardly to their active positions. The walls of the depressions 48 are adapted to cooperate with the stops 5I- to limit outward swinging of the knives. In practice the outward movement of the knives I3 is sufciently great for the knives to fully sever or cut through the wall of the tubing T. The lower ends of the blades 50 and the stops 5I are adapted to cooperate with the upper end of the carrier I2 vto transmit downward force from the sub I6 to the carrier. The upper end of the carrier I2 is hardened and smooth and the lower endsof the blades 50 and the stops 5I are at and smooth to bear on the upper end of the carrier with a minimum of friction. The blades 50 and the stops 5I may be integral with the sub I6, as illustrated in the drawings.

The means I4 is provided to normally hold the knives I3 in their retracted positions and to return or retract the knives after actuation. 'Ihe Ameans I4 is in the nature of a spring means and exerts a torque or turning force on the knife carrier I2. The opening 44 in the carrier I2 is enlarged throughout its major portion to receive the mandrel I0 with substantial clearance. The means I4 comprises a. helically wound torsional spring 53 arranged in the opening 44 to surround the mandrel I0. One end lof the spring 53 is secured to the mandrel I Il and the other end is secured to the carrier I2. In the construction illustrated the upper end portion of the spring 53 is set or secured in a `socket 54 in the mandrel IIJ. Aplate or washer A55 is secured to the lower end of the carrier I2 and the lower end portion of the spring 53 is secured in an opening 56 in the washer 55. The washer 55 may be secured to the carrier I2 by screws 51. The washer 55 forms an element of the friction brake means I 5,

as will be subsequently described. 'I'he spring 53 is normally or initially under torque and holds the carrier I2 in a rotative position where the knives I3 are retracted with their forward pivoted ends in contact with the rear sides of the blades 5I!v relative to the right hand direction of rotation, as illustrated in Fig. 2 of the drawings. The spring'53 is of suilcient strength to retain the knives I3 in their retracted positions when the tool is being run through the tubing T and to return the'carrier I2 and the knives to their normal positions after actuation of the tool, as will be hereinafter described. It will be vobserved that the carrier I2 forms a housing for the spring 53.

The friction means or friction brake means I5 forms a brake or drag between the carrier I2 and the tail-piece II being operable to resist rotation of the carrier I2 when the mandrel IIJ is vturned so that the carrier may lag relative to the sub I6 to effect actuation or outward feeding of the knives. The means I5 is responsive to or governed by a downward force on the mandrel I0 which may be varied at the will of the operator to control the outward feeding of the knives I3.

The means I5 includes the washer 55 mentioned above. The washer 55 maybe hardened and has a transverse or horizontal lower end. The means I5 further includes a part or collar 58 on the extension' 25 of the tail-piece body 23. The collar 58 may be threaded on the upperend of the extension 25 and may be locked in place by l `drel IIl and the collar is preferably of the same external diameter as the carrier I2 and the sub I6. The upper end of the collar 58 is engageable l by the lower end of the washer 55 and is preferably horizontal or parallel with the lower face of the washer. The lower end of the washer 55 or the upper end of the collar 58, or both, is roughened, serrated, grooved' or otherwise finished to constitute a friction surface. In the form of the invention illustrated in the drawings the upper end of the collar 58 is provided with a multiplicity of grooves I62 to provide for the desired movement resisting engagement between the opposing ends of the washer 55 and the collar 58. The

, lower end of the washer 55v and the upper end of the collar 58 may normally be in contact and the parts may b e related so that there is some clearance between the upper end of the carrier I2 and downwardly so that the washer 55 bears against the upper end of the collar 58.

In operation the tool may be assembled with the parts as shown in Fig. l of the drawings. The tail pie'ce II is collapsed, the ring 38 being threaded on the nut extension'22 and the knives I3 are in their retracted positions as illustrated in Fig. 2. The tool may be run into the tubing T on the lower end of the string S. When the cutter or tool has reached the desired position the string S is turned in a right-hand direction to unthread the nut extension 22 from the ring 30. Following the unthreading ofthe nut 22 from the 'ringB the string S is moved downwardly. The

downward movement of the mandrel Ill with the string S is transmitted to the tail-piece body 23 by the engagement of the washer 55 against the collar 58 on the body extension 25. When the tail-piece body 23 moves downwardly the inclined surfaces 26 cooperate with the slips 33 to force them outwardly into tight engagement with the interior of the tubing T. The slips 33 are operable to rmly engage the interior of the tubing T I ing the upper end of the carrier I2 cause orA tend to cause the carrier to turn vwith the sub IG. The blades 5U engaging the knives I3 assist in urging the carrier I2 to rotate. The downward pressure on the carrer I2 holds the lower end of the Washer 55 in frictional engagement with the grooved `upper end of the collar 58. 'Ihis frictional engagement between the lower end of the washer 55 and the grooved upper end of the collar 58 resists or rtends to resist* turning of the carrier lI2, the collar 58 being held stationary with the tail-piece I I, as described above. Thus the engagement between the lower end of the washer 55 and the upper end of the collar 58 causes the carrier I2 to lag relative to the rotating sub I6.

The lagging of the carrier I2 or the relative turning movement resulting from the frictional engagement between the washer 55 and the grooved upper end of the collar 58 results in the outward actuation or feeding of the knives I3. 'Ihe frictional engagement between the lower end of the washer 55 and the upper end of the collar 58 which may be varied by Varying the downward pressure on the mandrel Ill causes the carrier I2 to turn at a slower rate than the sub I6 so that the blades 50 act forwardly against the cam surfaces 41 of the knives I3 relative to the direction of rotation. 'Ihe blades 50 acting against the cam surfaces 41 swing or pivot the knives I3 outwardly bringing their cutting edges 46 in cooperation with the interior of the tubing T. The knives I3 rotating with the carrier I2 and fed outwardly by the blades 50 are operable to cut an annular groove or cut in the wall of 'the tubing T. It is to be understood that the outward feeding of the knives I3 may be readily controlled by the operator by varying the downward. force on the mandrel I and sub I6 to change the intensity of the frictional engagement between the lower end of the washer 55 and the upper end of the collar 58. The rotation of the string S accompanied by the desired downward force on the mandrel Ill and sub I6 may be continued until the knives I3 cut completely through the wall of the tubing T. The stops I are adapted to limit the outward feeding of the knives I3.

Subsequent to the making of the cut in the tubing T the string S may be moved upwardly and then rotated in a direction to thread the nut extension 22 in the ring 30. The upward movement of the string S is transmitted to the body 23 from the mandrel Ill by the upper end of the nut extension 22 engaging the lower end of the body. This upward movement of the body 23 retracts the slips 33. Following the threading of the nut extension 22 in the ring 3|) and the retraction of the slips 33 the tool may be withdrawn from the Well or may be moved to a different position 1n the well to make another cut in the tubing T.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the speclfic details herein set Iforth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

l. A tool for use on a well string to cut a tubular object in a well comprising a body adapted to be secured to the string and entered in the object, a member turnably supported on the body, means connecting the member with the body to turn therewith and yieldable to .allow relative turning between the body and member, a knife projectable into contact with the object upon relative turning between the body and asiooa'zz4 member, and means controllable by longitudinal manipulation of the string for resisting turning of the member with the body whereby rotation of the body projects the knife, the last mentioned means including slip means for gripping the object to be stationary therewith, and 'friction clutch means engaging between the member and the slip means.

2. A tool for use on a well string to cut a tubular object in a well comprising a body adapted to be secured to the string and entered in the object, a member turnably supported on the body, means connecting the member with the body to turn therewith and yieldable to allow relative turning between the body .and member, a knife projectable into contact with the object upon relative turning between the body and member, and means controllable by longitudinal manipulation of the string for resisting turning of the member with the body whereby rotation of the body projects the knife, the last mentioned means comprising an assembly having movement re` sisting engagement with the object, and a friction brake between the member and the assembly.

3. A tool for use on a well string to cut a tubular object in a well comprising a mandrel secured to the string to be entered in the object, a turnable member on the mandrel, a knife initially retracted clear of the object, means transmitting longitudinal force from the mandrel to the member and yieldingly urging the member to turn with the mandrel, means for projecting the knife upon relative turning movement between the mandrel and the member, and means governed by the intensity of the longitudinal force applied to the mandrel by the string for resisting turning of the member whereby rotation of the mandrel effects projection of the knife.

4. A tool for cutting a tubular object in a well comprising a mandrel to be entered in the object, a turnable member on the mandrel, a knife initially retracted clear of the object, means transmitting longitudinal force from the mandrel to the member and yieldingly urging the member to turn with the mandrel, means for projecting the knife upon relative turning movement between the mandrel and the member, and means controllable by applied longitudinal force on the mandrel for resisting turning of the member with the mandrel.

5. A tool for use on a well string to cut a tubular object in a well comprising a mandrel secured to the string to be entered in the object, a turnable member on the mandrel, a knife initially retracted clear of the object, means transmitting longitudinal force from the mandrel to the member and yieldingly urging the member to turn with the mandrel, means for projecting the knife upon relative turning movement between the mandrel and the member, and means controllable by the intensity of the longitudinal force applied to the mandrel by the string for resisting turning of the member with the mandrel, the last mentioned means including a tail piece on the body cooperable with the interior of the object, and a friction brake means interposed between the member and the tail piece.

6,. A tool for use on a well string to cut a tubular object in a well comprising a mandrel secured to the string to be entered in the object, a turnable member on the mandrel, a knife initially retracted clear of the object, means transmitting longitudinal force from the mandrel to the member and yieldingly urging the member to turn with the mandrel, means for projecting the knife to the mandrel by the string for resisting turning of the member with the mandrel, the last mentioned means including a slip assembly carried by the mandrel for gripping the object to be stationary therewith, and an element supported by the slip assembly and frictionally engaged by the member to receive longitudinal forces therefrom.

7. A tool for use on a well string to out a tubular object in a well comprising a -mandrel secured to the string to be entered in the object, a turnable member on the mandrel, a knife carried by the member and initially retracted clear of the object, means transmitting longitudinal force from the mandrel to the member and yieldingly urging the member to 'turn with the mandrel, means for projecting the knife upon relative turning movement between the mandrel and the l member, and means governed by longitudinal forces imposed on the mandrel by the string for resisting turning of the member whereby rotation of the mandrel effects projection of the knife.

8. A tool for use on a well string to cut tubing in a well comprising a mandrel secured to the string to be entered in the tubing, a member turnably carried on the mandrel,` pivoted knives on the member, parts on the mandrel cooperable with the knives to project them against the tubing upon relative turning movement between the mandrel and member, means yieldingly urging the member to turn with the mandrel, a tail piece carried by the mandrel and operable into gripping engagementwith the tubing, and friction means interposed lbetween the member and tail piece governed by longitudinal forces imposed on the mandrel'by the string to resist turning of the member.

9. A tool for cutting, tubing in a well comprising a mandrel to be entered in the tubing, a

member turnably carried on the mandrel, pivoted knives on the member, parts on the mandrel cooperable with the knives to project them against the tubing upon relative turning movement between the mandrelA4 and member, means yieldingly urging the member to turn with the mandrel, yielding means holding the member in a rotative position where the knives are retracted, a tail piece carried by the mandrel 'and operable into gripping engagement with the tubing, and friction means interposed between the member and tail piece for resisting turning of the member.

10. A tool /for cutting tubing in a well comprising a. mandrel to be entered in the tubing, a member turnably carried on the mandrel, pivoted knives on the member, parts on the mandral cooperable with the knives to project them against the tubing upon relative turning movement between the mandrel and member, means yieldingly urging ythe member to turn with the mandrel, means for returning the knives to their retracted positions after actuation, a tail piece carried by the mandrel and operable into gripping engagement with the tubing, and friction means interposed between the member and tail piece forresisting turning of the member.

11. A tool for cutting tubing in a well comprisy ing a mandrel to be entered in the tubing, a member turnably carried on the mandrel, pivoted knives on the member, parts on the mandrel cooperable with the knives to project them` against the tubing upon relative turning movement between the mandrel and member, means for` transmitting downward force from the mandrel to the member and vyieldingly urging the member to turn with the mandrel, a tail piece carried by the mandrel operable to grip the tubing, and frictionally engaging parts on the member and tail piece offering resistance to turning of the member proportionate to the intensity of the downward force on themember..

12. A tool for cutting tubing in a well comprising a mandrel to be entered in the tubing, a member turnably carried on the mandrel, pivoted knives on the member, parts on the mandrel cooperable with the knives to project them against -leasable means holding the tail piece inactive,

and friction means interposed between the member and the tail piece for resisting turning of the member.

13. In a well tool, a mandrel adapted to be entered in a tubular object, a body related to thel mandrel for relative longitudinal movement and having an inclined surface, a slip operable into cooperation wtih the object by said surface, spaced rings around the mandrel, springs connecting the rings and frictionally cooperating with the interior of the object to resist movement of the rings, and ngers on the rings cooperating with the opposite ends of the slip.

14. In a well tool, a mandrel adapted to be entered in a tubular object, a body related to the mandrel for relative longitudinal movement and having an inclined surface, a slip operable into cooperation with the object by said surface, spaced rings around the mandrel, springs connecting the rings and frictionally cooperating with the interior of the object to resist movement of the rings, there being notches in the ends of the slip and ngers on the rings cooperating with the notches whereby the body is movable relative to jectable against the tubing by relative turning between the mandrel and member,'means for transmitting downward force from the mandrel to the member, and means governed by longitudinal force applied to the mandrel by the string for oifering resistance to turning of the member proportional to the intensity 'of the downward force on the member whereby the turning of the mandrel-effects projection of the knives.

CLIFFORD HOWARD. 

